Cancer immunology is an emerging field in the area of cancer therapeutics that aims to utilize the body's own immune defenses to target and eliminate cancerous cells. The idea of using the body's own immune system to attack cancer cells has many advantages over traditional therapies that are site specific, such as radiation and surgery, or over chemotherapeutic methods that are associated with detrimental side-effects and high toxicity.
This field was significantly advanced by the identification and characterization of many different tumor-specific antigens. These tumor-specific antigens are specific to the cancerous cells themselves. If an immune response could be launched that targets these tumorspecific antigens, the body would effectively be able to clear cancerous cells on its own. However, strategies to induce tumor-specific immunity in patients have thus far been unsuccessful. Studies suggest that there are various factors that contribute to the failure of current cancer immunotherapeutic strategies. First, these strategies fail to sufficiently expand circulating cytotoxic T cell lymphocytes. Second, cancer patients are often immunosuppressed and fail to produce the co-stimulatory molecules necessary to initiate an immune response. Therefore, a major goal of cancer immunotherapy has been to generate a large number of high-avidity tumor-specific T cells that can efficiently attack cancerous cells in vivo.
The present invention uses a nanoparticle coated with tumor-specific antigen/MHC complexes and co-stimulatory molecules. This unique complex can induce an expansion of circulating CD8+ T cells in an amount that surpasses that of current cancer immunotherapies.